* Sound support
* I'm implementing groach as a timer driven.
  It's easier to implement and easier to control,
  but it might hit performance more than xroach, which uses root window's
  exposure event.
* More themes.
* I want to make it easier to create a new theme.

Known bugs:
* In my environment, the speed scale widget on groach_applet dosen't work after
  changing theme. I don't know the reason.
  It looks a bug of combo box, but I'm not sure.
